The present invention relates generally to folding bed frame structures of the type utilized in sofa beds or the like and more particularly relates to spring support arrangements employed therein for seating and sleeping support.
Convertible sofa beds having widely varying types of folding bed frame structures are in common use. The folding bed frames of such sofa beds characteristically employ a plurality of frame sections pivotally connected in end-to-end relation in combination with a linkage arrangement operatively associated with the frame sections for mounting of the structure within the rectangular enclosure of a sofa bed frame and for controlling the folding and unfolding movements of the frame sections between a retracted condition folded within the sofa frame enclosure and a horizontally extended condition extending outwardly therefrom. A wire and spring link-type support fabric or deck is typically provided across the longitudinal and transverse extents of the frame sections on which is supported a matress of relatively small thickness, the link-type fabric and the matress being readily foldable and thereby facilitating the necessary folding and unfolding movements of the folding bed frame structure. As will thus be understood, the link-type fabric and the matress provided substantially the only means of support for seating in the folded condition of the structure and for sleeping in the extended condition of the structure. For this reason, sofa bed structures of this general type are generally recognized to provide inferior seating comfort in the folded condition making the sofa beds in which they are used relatively undesirable if to be used for seating purposes primarily. Nevertheless, such sofa beds have achieved a relatively wide degree of popularity due primarily to the flexibility and versatility they lend in providing both a seating and a sleeping function.
In contrast, the present invention provides a novel improvement in sofa bed frame structures of the above-discussed type which advantageously permits incorporation into one frame section of the structure of sinuous-type springs such as are used conventionally in ordinary, non-convertible sofa furniture, whereby substantially greater and more comfortable seating support is provided in the present sofa bed frame structure without impairing the ordinary and desirable folding and unfolding operation of the structure.